Secondary, or rechargeable, lithium ion batteries are used in many stationary and portable devices, such as those encountered in the consumer electronic, automobile, and aerospace industries. The lithium ion class of batteries has gained popularity for various reasons, including a relatively high energy density, a general non-appearance of any memory effect when compared to other kinds of rechargeable batteries, a relatively low internal resistance, a low self-discharge rate when not in use, and an ability to be formed into a wide variety of shapes (e.g., prismatic) and sizes so as to efficiently fill available space in electric vehicles, cellular phones, and other electronic devices. In addition, the ability of lithium ion batteries to undergo repeated power cycling over their useful lifetimes makes them an attractive and dependable power source.